# Copyright 2021 Huawei Technologies Co., Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ============================================================================

"""PSNRLOSS"""

import mindspore.nn as nn

class PSNRLoss(nn.Cell):
    """Loss for srresnet"""
    def __init__(self, generator):
        super(PSNRLoss, self).__init__()
        self.generator = generator
        self.pixel_criterion = nn.MSELoss()
    def construct(self, HR_img, LR_img):
        hr = HR_img
        sr = self.generator(LR_img)
        psnr_loss = self.pixel_criterion(hr, sr)
        return psnr_loss
